Focus: Clocks and Cycles: Clocks and Cycles

An organism’s fitness depends on their ability to adapt to their environment. So perhaps it is no surprise that multicellular organisms ranging from plants to animals--vertebrates and invertebrates alike--live by a daily biological rhythm that is set by the Earth’s rotation and orbit around the sun. During the daily 24-hour cycle, an individual’s physiology, behavior, and well-being can vary greatly, often in synchrony with environmental changes by a process called entrainment. These organismal-level changes occur due to corresponding fluctuations in cycle-specific molecules, such as proteins aptly named CLOCK and PERIOD, at the cellular level. In 2017, Jeffrey C. Hall, Michael Rosbash, and Michael W. Young were jointly awarded the Nobel Prize in Physiology & Medicine for their efforts in discovering and elucidating key mechanisms underlying circadian (or daily) rhythms. Therefore, we feel that an issue dedicated to the inner workings of circadian cycles in both plants and animals is timely